Abstract: There are disclosed certain bis(aminoethanethiols) and the salts thereof which find utility as intermediates in the preparation of certain dye-providing compounds useful in photographic imaging systems.

Abstract: There are disclosed color-providing compounds comprising two or more cyclic 1,3 sulfur-nitrogen groups and two or more color-providing moieties, i.e., complete dyes or dye intermediates, capable of releasing the color-forming moieties upon cleavage in the presence of silver ions or a soluble silver complex. The color-providing compounds are useful as image-forming materials in color photographic processes.

Abstract: Disclosed is a class of bridged phthalides and sulfinate esters which exhibit reversible thermochromism. At room temperature and in the presence of base, these compounds are substantially colorless but upon the application of heat they become colored, reverting to their original colorless or weakly colored state upon cooling. This colorless to colored, temperature-dependent cycle can be repeated many times. These compounds have utility as temperature sensors and as thermal pH indicators.

Abstract: Certain squaric acid derivatives are useful for the thermochemical generation of acid. The squaric acid derivatives may be used in imaging media in conjunction with acid-sensitive materials which undergo a color change when contacted by the acid generated from the squaric acid derivatives. Preferably, the acid-sensitive materials undergo an irreversible color change, so that the image can be fixed by neutralizing all the acid generated with excess base, thereby preventing further color change in the image during long term storage.

Abstract: A novel class of N-substituted triarylmethane sulfonamides is provided which undergo reversible oxidation into colored form and reversible reduction of the oxidized form into colorless form. Preferred embodiments comprise xanthene sulfonamides having N-aryl substituents, e.g., hydroquinone substituents. These compounds possess redox potentials ranging between about +200 to -500 millivolts and thus are useful as dyes for producing photographic, photothermographic, thermal, and pressure-induced images, as well as being useful as redox indicators in a wide variety of biological and chemical reactions.

Abstract: A novel class of bridged indicator dyes is disclosed which possess absorption in the infrared region of the electromagnetic spectrum. These bridged indicator dyes are useful as light-absorbing, pH-sensitive optical filter agents in diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes. These indicator dyes will also find utility in titrations and other analytical techniques and products where pH-sensitive indicator dyes are employed and absorption of infrared is useful.

Abstract: A mixed carbonate ester of a quinophthalone dye and a tertiary alkanol containing not more than about 9 carbon atoms, preferably a compound of the formula: ##STR1## wherein X is a sulfur atom or a carbonyl group; each Y independently is a hydrogen atom, a halogen atom, a --CO--OR.sup.4 or a --CO--NHR.sup.4 group, wherein R.sup.4 is an alkyl group containing not more than about 10 carbon atoms; R is a hydrogen atom or an --O--C(.dbd.O)--O--CR.sup.5 R.sup.6 R.sup.7 group; and R.sup.1, R.sup.2, R.sup.3, R.sup.5, R.sup.6 and R.sup.7 are each an alkyl group, subject to the proviso that R.sup.1, R.sup.2 and R.sup.3 together contain a total of not more than about 8 carbon atoms, and R.sup.5, R.sup.6 and R.sup.7 together contain a total of not more than about 8 carbon atoms.

Abstract: Leuco dyes are provided which comprise the coupling product of a N-acyl substituted aromatic amino color developer and a dye-forming coupler moiety substituted at the coupling carbon with a thermally removable leaving group. Thermal imaging systems employing these leuco dyes have the advantage of reduced bubble formation relative to thermal imaging systems employing prior art leuco dyes containing a group which thermally fragments into one or more gases.

Abstract: A thermal imaging method for forming color images is provided which employs as the color image-forming material, a colorless precursor of a preformed image dye possessing at least one thermal protecting group that undergoes fragmentation upon heating and at least one leaving group that undergoes irreversible elimination upon heating, said protecting and leaving groups maintaining the precursor in its colorless form until heat is applied to effect removal of these groups whereby the precursor is converted to an image dye.

Abstract: This invention relates to diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes wherein a substantial increase in opacification in the red and near infrared region of the visible spectrum and a substantial increase in opacification in the blue and green region is achieved by employing certain alkyl-substituted phenanthrol/carboxynaphthol phthaleins as the light-absorbing, pH-sensitive optical filter agent for the longer wavelength region of the visible spectrum.

Abstract: There are disclosed certain aminoether compounds which are useful as intermediates in the preparation of photographic image dye providing materials. The aminoethers are represented either by the formula ##STR1## wherein R is hydrogen or an alcohol protecting group and R.sub.1 is hydrogen, alkyl or aralkyl such as benzyl or phenethyl; or the formula ##STR2## wherein R.sub.2 and R.sub.3 are alkyl having from 1 to 6 carbon atoms or R.sub.2 and R.sub.3 together represent the carbon atoms necessary to form, together with the oxygen atoms to which they are bonded and >CH, a five or six member saturated heterocyclic moiety which may include substituted rings and fused rings.

Abstract: Photographic products and processes for the imagewise generation of a dye from a color shifted dye precursor of a preformed image dye, said precursor having at least one ##STR1## group, wherein R is hydrogen, alkyl, provided that the .alpha.-carbon does not have a hydrogen atom attached thereto, aryl such as phenyl or substituted phenyl, e.g. p-nitrophenyl, or heterocyclic such as pyridine; R.sub.1 -R.sub.6 are hydrogen, alkyl, preferably having from 1 to 6 carbon atoms, or aryl; n is 0 or 1; and T is a moiety containing a thiazolidin-2-yl group which upon silver-assisted cleavage of said thiazolidin-2-yl group results in the formation of a ##STR2## group, which may be protonated under the reaction conditions, followed by cleavage of said ##STR3## which cleavage is anchimerically assisted or accelerated by said ##STR4## to provide after protonation, an ##STR5## group in a dye chromophore. In a preferred embodiment the precursor is a substantially colorless compound.

Abstract: Photographic products and processes for the imagewise generation of a dye from a color shifted dye precursor of a preformed image dye, said precursor having at least one ##STR1## group, wherein R is hydrogen, alkyl, provided that the .alpha.- carbon does not have a hydrogen atom attached thereto, aryl such as phenyl or substituted phenyl, e.g. p-nitrophenyl, or heterocyclic such as pyridine; R.sub.1 -R.sub.6 are hydrogen, alkyl, preferably having from 1 to 6 carbon atoms, or aryl; n is 0 or 1; and T is a moiety containing a thiazolidin-2-yl group which upon silver-assisted cleavage of said thiazolidin-2-yl group results in the formation of a ##STR2## group, which may be protonated under the reaction conditions, followed by cleavage of said ##STR3## which cleavage is anchimerically assisted or accelerated by said ##STR4## to provide after protonation, an ##STR5## group in a dye chromophore. In a preferred embodiment the precursor is a substantially colorless compound.

Abstract: This invention relates to a class of phthalein indicator dyes useful as optical filter agents in photographic processes to protect a selectively exposed photosensitive material from further exposure during processing in the presence of incident light. Such dyes comprise 3,3-disubstituted phthalides and 3,3-disubstituted naphthalides wherein the 3,3 substituents are p-hydroxy carbocyclic aryl radicals wherein one or both of the radicals possess a --CH.sub.2 --NRR' group ortho to the p-hydroxy group and the --CH.sub.2 --NRR' group(s) is capable of rendering the indicator dye substantially non-diffusible in aqueous solution.